PETER HAIN has refused to be drawn on a referendum on the European Constitution after being named as one of six Cabinet heavyweights pushing for some form of public poll.

PETER HAIN has refused to be drawn on a referendum on the European Constitution after being named as one of six Cabinet heavyweights pushing for some form of public poll.

A string of reports suggest the Prime Minister is considering a major U-turn on the controversial blueprint for Europe after repeatedly refusing to stage a referendum.

Tony Blair is understood to have won support for a change of tactic ahead of the June 10 European elections from key Cabinet members including the Welsh Secretary, Foreign Secretary Jack Straw, Deputy Prime Minister John Prescott and even Chancellor Gordon Brown, under certain conditions.

As Downing Street sought to downplay the reports yesterday, Mr Hain kept silent when he was asked about the constitution while speaking to journalists about his trade trip to China.

He said, "I have no comment to make on that story."

Welsh MEP and European Conservative group leader Jonathan Evans joked, "It is extraordinary reticence on the part of Peter Hain.

"No doubt his recent trip to China has converted him to a Buddhist monk."

As a former Europe Minister, Mr Hain has twice fallen foul of the constitution he helped draw up.

He caused howls of protest from the Conservatives when he suggested the blueprint for an expanded EU was mainly a "tidying up exercise" of existing treaties.

And he was forced to back track after suggesting the European elections could serve as a de facto referendum on the issue.

"Our consistent position has been 'no' to a referendum on Europe," a Number 10 spokeswoman said.

However a specific referendum was not the only idea floated in yesterday's reports, another proposal suggested that approval of the constitution could form part of Labour's next manifesto.

Mr Evans said the stories bore the hallmarks of some "kite flying" by the Government ahead of the European elections on June 10, where Labour is expected to fare badly at the ballot box.

"They throw it out, they draw it back - just to see what sort of reaction there is.

"They know they are vulnerable on the constitution and want to see how they can deflect the level of public interest on it. My own view is that it is extremely unlikely that Blair will allow a referendum."

The Conservatives, who launched a petition calling for a referendum at the party's Welsh spring conference in Llandudno, said the Prime Minister should come clean about where he stands.

Any climb down would be seen as an attempt to head off the campaign by the Tories to turn the European elections into a vote on the constitution.

Welsh Liberal Democrat leader Lembit Opik said the Prime Minister should not use the General Election as a means to mandate the constitution.

He added, "The last time people used a manifesto as a referendum they voted for Labour because they promised to legislate against the introduction of top up fees but they have legislated for their introduction - so the Prime Minister should understand if people are a bit sceptical. The best way to let people decide is simply to have the referendum."

Rhondda MP Chris Bryant, of the Labour Movement in Europe, said he was "confident" the public would support Britain signing up to the constitution but a referendum on treaty negotiations was not necessary.

Member states are expected to reach agreement on the blueprint in June, after a row over voting rights for smaller countries in the new 25 state union stalled talks last year.